key-normalizer.h

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// Copyright 2012 Cloudera Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef IMPALA_UTIL_KEY_NORMALIZER_H_
#define IMPALA_UTIL_KEY_NORMALIZER_H_

#include "exprs/expr.h"

namespace impala {

//
//
//
class KeyNormalizer {
 public:
  KeyNormalizer(const std::vector<ExprContext*>& key_exprs_ctxs, int key_len,
      const std::vector<bool>& is_asc, const std::vector<bool>& nulls_first)
      : key_expr_ctxs_(key_expr_ctxs), key_len_(key_len), is_asc_(is_asc),
        nulls_first_(nulls_first) {
  }

  bool NormalizeKey(TupleRow* tuple_row, uint8_t* dst, int* key_idx_over_budget = NULL);

 private:
  static bool WriteNullBit(uint8_t null_bit, uint8_t* value, uint8_t* dst,
      int* bytes_left);

  template <typename ValueType>
  static void StoreFinalValue(ValueType value, void* dst, bool is_asc);

  template <typename IntType>
  static void NormalizeInt(void* src, void* dst, bool is_asc);

  template <typename FloatType, typename ResultType>
  static void NormalizeFloat(void* src, void* dst, bool is_asc);

  static void NormalizeTimestamp(uint8_t* src, uint8_t* dst, bool is_asc);

  static bool WriteNormalizedKey(const ColumnType& type, bool is_asc,
      uint8_t* value, uint8_t* dst, int* bytes_left);

  static bool NormalizeKeyColumn(const ColumnType& type, uint8_t null_bit, bool is_asc,
      uint8_t* value, uint8_t* dst, int* bytes_left);

  std::vector<ExprContext*> key_expr_ctxs_;
  int key_len_;
  std::vector<bool> is_asc_;
  std::vector<bool> nulls_first_;
};

}

#endif